Apparatus for irradiating resin vessels such as PET bottles with an electron beam for sterilizing the same have been widely known in conventional technology. It is also conventionally known that the resin vessel is electrostatically charged by being irradiated with the electron beam for sterilizing the vessel (for example, refer to Japanese Patent Application Laid-open Publication No. 2007-126171: Patent Publication 1).
This Patent Publication 1 discloses a PET bottle drink filling system having a structure in which the PET bottle entering from an entrance port is conveyed to a sterilization section by a food vessel conveying device, and then, is sterilized by being irradiated with the electron beam from an electron beam irradiating device. The sterilized PET bottle is then conveyed to a wash-out rinser so as to be cleaned by water or air. The PET bottle discharged out of the rinser is filled up with inner content by a filling device. The PET bottle filled up with the inner content is then applied with a cap by a capper so as to seal the PET bottle.
With the structure disclosed in the above Patent Publication 1, since the PET bottle is electrostatically charged with the irradiation from the electron beam, it is necessary to arrange a charge amount measuring device for detecting the charge amount, and the measured charge amount is sent to a computer from the charge amount measuring device to analyze the charge amount so as to judge whether the charge amount of the PET bottle generated by the irradiation with the electron beam is within a predetermined range or out of range.
If the resin bottle is electrostatically charged, dirt or dust may be attracted thereto, thus arising an inconvenient matter. Then, various apparatus or devices have been conventionally proposed to remove the static electricity charging the resin vessels (for example, refer to Japanese Patent Application Laid-open Publication Nos. 2000-68093 and 2004-14319: Patent Publications 2 and 3).
In the invention concerning a static electricity removing method and apparatus disclosed in the above Patent Publication 2, the static electricity is removed by irradiating a resin hollow vessel with an X-ray. Further, in the invention concerning a static electricity removing apparatus disclosed in the above Patent Publication 3, a loop nozzle curved in form of loop and formed with an air discharging port is provided for discharging air against an outer surface of a bottle and a straight nozzle formed with another air discharging port for discharging air against an inner surface of the bottle, and by blowing ionized air from these nozzles to the outer and inner surfaces of the bottle, the static electricity charged on these surfaces is thereby removed.
It may be possible to reduce the charging on the inner and outer surfaces of the resin vessel (bottle) by removing the static electricity by the method and/or apparatus disclosed in the Patent Publications 2 and 3. However, even by these methods and apparatus, it was difficult to remove the charge accumulated inside the resin material (substance) itself forming the bottle.